The northern parula is a small American wood warbler. In mixed flocks they are usually one of the smallest birds with kinglets typically being the only smaller species. They breed in the eastern United States and southeastern Canada. They winter in southern Florida, Caribbean, and Central America.
The northern parula breed primarily in forested habitat. The build pendulum styled nest from hanging vegetation. Birds in the north tend to use beard moss or coniferous twigs for nest construction while southern populations tend to use Spanish moss. In the middle, the southern Great Lakes region, northern parula do not breed. It is possible that this is because most of the habitat in these areas lack of epiphytes, plants that grow on other plants, that they look for to build the nests.
These birds were all photographed during migration. The top two were photographed near my home in southern Minnesota in May. Northern parula only nest in north eastern Minnesota where there are a lot of boggy areas that have trees with moss growing on them. The bottom shot was taken on South Padre Island in Texas. Northern parula do nest in east Texas but not usually that far south. This little water fountain was a first stop for many birds after making the long flight across the Gulf of Mexico.